In Northern California, Wesley Hull grew up fishing on the shores of Humboldt Bay with his father. In this quiet corner of the state, shucking is more than a task—it’s a ritual of patience, grit and deep connection to place. As a kid, he and his father would spend hours on the water or in the mud, fishing and harvesting shellfish. They frequently visited the docks where they chatted with other community members and commercial fisherman – some of whom his father had previously built relationships with through construction work. These early experiences sparked Wesley’s interest in estuarine environments, but also the people most connected with them. As a graduate student he maintained his connection to this environment and community by working as an oyster farmer while studying biology.
"As a kid, I was given the opportunity to learn about and be a part of my local fishing and farming community, which has helped me understand how science can inform the challenges these types of communities are face.”
Wesley Hull standing in one of the tide flats.
Hull, Ph.D. Philosophy from the Department of Biology at the University of Washington, is this year’s Graduate School Medal Award winner. This award is given to recognize doctoral candidate “scholar-citizens,” whose academic expertise and social awareness are integrated in a way that demonstrates active civic engagement and a capacity to promote political, cultural and social change.
His research explores how burrowing shrimp impact key habitat-forming species—both ecologically and economically—and how these changes affect shellfish farmers in Washington’s outer coast communities. With the help of the biology department, Washington State Sea Grant and shellfish farmers, he has examined ecosystem engineers, animals that can modify their habitats through the creation of structure or physical behavior, and how they interact with one another.
“Burrowing shrimp in the outer coast estuaries in Washington are abundant,” explains Hull. “They can exist at very high densities and transform large areas of a tide flat.”
Research on the Coast
The estuarine environments in Washington—especially in the outer coast regions—are perfectly suited for burrowing shrimp. The conditions support not only their growth but also their role as ecological engineers. Their sheer abundance and constant burrowing drastically alter the surface of tide flats, exerting a strong impact on the aquaculture industry—one that’s becoming increasingly difficult to ignore.
For shellfish farmers along Washington’s outer coast, burrowing shrimp presents a significant challenge. Traditionally, many growers rely on a low-maintenance, natural method to cultivate oysters. They scatter clutch—tiny shells covered in tiny oysters—across the surface of the tide flats during high tide. Then, they wait. Over the course of several years, those tiny oysters mature into larger clusters of oysters, which can later be harvested, separated and sold either whole or as shucked product.
Unfortunately, burrowing shrimp makes this a difficult process. As they burrow, excavated sediments are ejected to the surface—coarser particles settle quickly, while finer particles remain suspended in the water column before eventually settling in the surrounding area. This burrowing behavior acts like a sediment-conveyor belt, cycling coarser sediment back into the tide flat and gradually transporting fine sediments out of the bed. “They end up burying those oysters with that ejected sediment, causing them to suffocate and die,” Hull explains. The result is a tide flat that becomes soft and unstable. Through his research, he identified the shrimp densities and mechanisms responsible for declining oyster survival.
Hull’s research looks to understand not just the oyster-shrimp conflict, but also how burrowing shrimp interacts with another key player in the ecosystem: eelgrass.
“Eelgrass is another important ecosystem engineer,” says Hull. Unlike shrimp, which destabilize sediment, eelgrass helps stabilize it. As a marine plant, it grows upright in the water column, providing habitat for diverse assemblages of fish and invertebrates, and causes suspended sediments to settle on the surface, helping stabilize the tide flat.
“Eelgrass modifies its environment in a different way,” Hull explains. “It creates a more stabilized tide flat, with higher proportions of mud and organic material. It’s kind of the opposite of what shrimp are doing.”
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Wesley Hull sampling across borders between burrowing shrimp and eelgrass habitats to infer their interactions during one of our summer heatwaves.
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Wesley Hull pumping shrimp out of the tideflat
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Wesley Hull with my arms in the ground is what happens to oysters when they are in dense shrimp, they get buried by ejected sediments.
Yeilding Results
For his dissertation, Hull set out to discover which species dominate when these two engineers meet. Previous studies in California had shown eelgrass winning out, with dense mats of rhizomes—or underground plant stems—forming physical barriers that kept shrimp at bay. But in Washington, things were different.
“Eelgrass [in the outer coast] tends to grow larger but in lower densities,” he says, “and that begged the question—does eelgrass still dominate in these lower-density systems?”
Hull conducted a series of surveys, observing the distributions of shrimp and eelgrass across habitat boundaries. “Imagine a solid vertical line,” he says, “on one side you have an eelgrass bed, and on the other, bare habitat that could have shrimp. I quantified shrimp and eelgrass across that boundary.” Additionally, he transplanted eelgrass into shrimp beds to investigate whether the life stage of eelgrass at the time of interaction influenced the outcome.
The results were telling. “It didn’t really matter how much eelgrass there was,” Hull notes. “Burrowing shrimp were always present. I never found a sample with no shrimp in eelgrass.” On the other hand, eelgrass was never present above moderate shrimp densities, and newly emerged eelgrass seedlings were more susceptible to their burrowing activities than adult shoots.
His findings confirmed what many farmers had long suspected: it’s not just the presence of shrimp, but their relentless burrowing and sediment reworking that turns a productive oyster bed into a graveyard. He also showed that eelgrass could not serve as a nature-based solution for reducing shrimp abundance. Hull was able to present his findings to farmers in a way that translated his science into practical, accessible insights that were relevant, validating what farmers had long suspected based on ecological knowledge and experience as stewards of their own systems.
Building trust and understanding was key for Hull. “We meet with farmers and others from academia and government and ask what their concerns were and how do we tackle them,” Hull recalls. In many cases, he had the opportunity to meet with farmers who granted him access to their land— not only to talk about his research but also ask to seek their advice and guidance. “I want to incorporate their ideas and what they were thinking, because I want this to be more than just self-satisfying.’”
The collaboration between science and farmers helped Hull earn this prestigious award. At first, he was surprised that he had been nominated. Stating that he wasn’t an honor roll student but felt honored to be nominated by his department and committee. “It was validating to know that my work had made such an impact on people and to be recognized,” Hull says.
His biggest piece of advice for awardees nominated next year is to explain the impact your work had on the communities you worked with or are most closely connected to. “Rather than focusing solely on science, I chose to explain the origin of my work and what that meant to those communities involved,” Hull explains. “This was a great conclusion to my academic career.”
By: Tatiana Rodriguez, UW Graduate School
Published on June 18, 2025